Circuit breaker switch



Jan. 22, 1952 c ROUSSEAU 2,583.122

CIRCUIT BREAKER SWITCH Filed Oct. 20, 1949 2 SHEETSSHEET l 5' zo i IIIIIIIIII,IIIIIIIIIIIIIIIA 1952 c. ROUSSEAU CIRCUIT BREAKER SWITCH 2 SHEETS-SHEET 2 Filed Oct. 20, 1949 Patented Jan. 22, 1952 UNITED STATES PATENT OFFICE Application October 20, 1949, Serial No. 122,430 In Canada October 25, 1948 3 Claims. 1

The present invention relates to a combina tion switch and circuit breaker.

More specifically, this invention relates to a manually operable on-off" switch which is also capable of automatically opening the circuit controlled thereby under overload conditions, or short-circuit.

The main object of the invention is to provide an improved device of the character set forth above in which the switch handle always indicates the actual position of the switch mechanism, that is, when the circuit breaking mechanism has tripped to open the circuit, the switch handle moves to the off or open circuit position.

An auxiliary objective of great importance is to provide a combination switch and low voltage air circuit breaker of generally improved and simplified design having a quick-break and quickmake contact mechanism.

Another object is to provide a circuit breaker of the type set forth wherein a bimetallic thermostatic element trips the circuit breaking mechanism under overload conditions and yet is at no time subjected to any undue stress or frictional resistance on the part of the mechanism.

Other objects and advantages will become apparent, or be further pointed out, in the description to follow.

As an example, and for purposes of illustration only, preferred embodiments of my invention are shown in the annexed drawings, wherein:

Fig. 1 shows a diagrammatic plan of one form of the switch circuit breaker when in closed circuit position;

Fig. 2 shows a similar plan view only with the mechanism in open circuit position;

Fig. 3 shows a sectional view along the line I! of Fig. 1;

Fig. 4 shows a similar sectional view only with the mechanism in open circuit position;

Fig. 5 shows a sectional view along the line 5-5 of Fig. 2;

Fig. 6 shows in enlarged detail a section along the line 88 of Fig. 3;

Fig. 7 shows a similar view along the line of Fig. 4;

Fig. 8 shows an elevation view, partly in section, of one end of the member provided for manual operation of the switch;

Fig. 9 shows, in diagrammatic outline, a plan View of a circuit breaking mechanism in closed circuit position constructed as an alternative and simplified form of the invention;

Fig. 10 shows a diagrammatic plan similar to Fig. 9 but with the mechanism in open circuit position, and

Fig. 11 shows a detail view in elevation oi the mechanism of Figs. 9 and 10.

Referring now to the drawing, wherein the same reference characters indicate corresponding parts throughout, the device will be seen to consist mainly of a switch member pivotable between open circuit and closed circuit positions, a contact unit also pivotable to close or open the circuit, spring means urging each of these elements into their open circuit position, means releasably holding them in closed circuit position after being displaced thereto by manual operation of the switch member, and finally a current responsive device adapted to release, under overloaded conditions, or short circuit, the means holding the aforementioned elements in circuit closing position.

One effective embodiment of the invention is shown in Figs. 1 to 8 inclusive. A simplified alternative construction is exemplified, in its irnportant details, in Figs. 9 to 11.

In Fig. 1, the switch member of the device is seen to consist of a hub l5 from which a handle or actuating member l6 projects through a slot IT in the face plate ill. The rest of the mechanism lies behind the face plate and may be en closed in a box shaped casing as indicated by IS, the terminals by which the device is connected in the circuit projecting at.20.

Inside the casing, hub I5 is pivoted at 2| and has means tending to hold the switch member in its off, or open circuit position (the lower position in Figs. 1 and 2), such as a spring 22 coiled around the hub and abutting against the inside of the face plate. Also pivoted inside the casing and swinging in a plane parallel to the movement of the switch member, is a contact lever 23, said lever having a so-calied snap action for quick make-and-break of the switch contacts, this quick action being obtained by means of a simple toggle-operated tripping member 24 pivotally secured to the lever at the pivotal point 25 thereof.

For a purpose hereinafter set forth, a spring 26 is provided tending to hold the tripping member out of alignment with lever 23, and is compressed between two of the ends of these members. A further spring 21 is compressed between the back wall of the casing and an edge of tripping member 24, tending to urge the latter to swing in a direction towards the switch member.

Slidably journalled eccentrically in hub [5, parallel to the axis of the latter, is a pin 29. This pin carries a head 30 at one end and a projecting arm 3| at the other end thereof (as shown in Figs. 3 to 8). This arm 3| is thus movable transversely relative to the swinging movement of the switch member, although it will normally be held in a predetermined position by the effect of a spring 32 surrounding pin 29 underneath head 30 and in a recess formed in hub IS. The said spring 32 causes arm 3| to normally adopt such a position as will render it co-operable with an extension 34 on the tripping member. Hence, as the switch member is moved from its off to its on position, arm 3| abuts extension 34 and causes a pivoting of the tripping member away from the switch member, against the force of spring 21. As the switch member takes up its on position indicated in Fig. 1, the tripping member is disposed at its most remote position near the back wall of the casing and the force of spring 26 urging the lever 23 out of alignment with the tripping member causes closure of the circuit by contact 35 on the free end of the lever. This position will be maintained, even against the force of springs 22, 26 and 21, by the engagement of arm 3| with extension 34. These co-operative member may be provided, if desired, with retaining notches or co-operative formations on the surfaces thereof to maintain this engagement.

To open the circuit, means will be provided acting on the head 38 of plunger pin 29 in order to move arm 3| or release the latter transversely out of engagement with extension 34. Such means are preferably provided in the form of a bimetallic current-responsive element 36 projecting in to the casing from a mounting electrically integral with one of the terminals 20. The inwardly projecting head of element 36 is connected to the contact block by means of a flexible lead such as 31. Hence, when current flows during closed circuit conditions, the resultant heating of the bimetallic element will cause a warping of same as is well known in the art, the extent of the warp or bend being determined by the amount of current flowing. The element 36 will be so located that when the mechanism is in closed circuit position, the free end of the element will be immediately adjacent head 30 of pin 29. Hence, any warping of the element beyond a predetermined amount will cause displacement of the pin and hence of arm 3|. By this means is efiected a release of the co-operative locking members 3| and 34 and hence a tripping of the mechanism to open the circuit. This will occur whenever the bimetallic element is sufliciently warped by overloaded conditions.

An important feature of the mechanism described above resides in the fact that when the mechanism trips the switch handle, member l6 also moves to its ofi position, thus indicating to the casual observer that the circuit is open. On the other hand, even greater advantages are realized by the mechanism in the interests of safety. For, if the circuit has tripped open and the conditions which lead to the overloaded circuit still prevail, the circuit cannot be closed simply by operation of switch member I6.

For, if the switch member be manually displaced to its "on position, the excessive current flowing will immediately cause warping of the bimetallic element and hence will release arm 3| from its engagement with the extension on the tripping member. The mechanism will hence open the circuit even though the switch be held in the on position.

A simpler and alternative form of construction for a circuit breaker according to the present invention is shown in Figs. 9 to 11. In this case. there is no tripping member journalled on the contact lever and the latter is alone pivoted adjacent the switch member. A single spring 40 urges the contact lever to open contacts 4| and hence break the circuit. The same spring tends to urge the other end of the contact lever inwardly towards the switch member, upon which latter there is provided means releasably en gageable with the projecting portion 42 of the lever. As a preferred arrangement, an inwardly extending portion 45 is provided on the hub of the switch member and a pin 46, carrying a head 41 on one end and a roller 48 on the other end, is journalled so as to be transversely movable in this extension. A spring 49 tends to urge the pin to a position where roller 48 will be in alignment to co-operate with the lever 42.

As before, a bimetallic element is provided 68 and in this case fits underneath the head 41 of pin 46 to obtain an effective purchase on the latter. When excessive current causes a warping of the element 58, the latter moves in the direction of the arrow in Fig. 11 and carries with it the pin and roller 48 which is accordingly displaced out of engagement with the lever.

Spring 48 hence causes the lever to move into open circuit position whilst another spring may be provided on the switch member, similar to spring 22 to cause the latter in turn to move to its ofl." position. When the switch member is in its oif position, spring 49 restores roller 48 to its former location relative to the switch member and hence, when the latter is manually pushed into its own position, it carries with it the lever in order to once more close the circuit. In its effect, the arrangement indicated in Figs. 9 to 11 is identical with that indicated in Figs. 1 to 8.

From the foregoing, it will be readily appreciated that the present invention fulfills the objectives set forth. Whilst of simple and practical design, the device carries out very desirable effects, such as indicating at all times the position of the mechanism having a quick-break and quick-make contact action, and greatly enhanced safety precautions. The nature of the mechanism by which the device trips, the warping of the bimetallic element simply pushing a small pin and arm sideways, is such that little or no stress is placed on the bimetallic element and hardly any resistance offered to its natural warping.

Accordingly, none of the mechanism is overstrained or is subject to damage or wear in use.

It will therefore be understood that I do not limit myself to the particular embodiments of my invention herein shown and described, since clearly various alterations might be made in the size, shape, and arrangement of parts, without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. In a circuit-breaker device of the character described, a switch member pivotable between open and closed circuit positions, a circuit-closing contact lever pivoted spacedly relative to the switch member and movable arcuately in a plane parallel thereto between circuit-closing and circuit breaking positions, a tripping member pivoted to said lever and movable in a plane parallel in switch member movement, spring means urging the switch member to the open-circuit position, a tog le spring compressed between the lever and one end of the tripping member so as to urge the latter out of alignment with the lever, means releasably engageabie between said switch member and said tripping member so as to hold same and the lever in circuit-closing position when the switch member is so disposed, a third spring urging said tripping member and hence the lever out of circuit-closing position against the force of said toggle spring, and a load-responsive device in said circuit movable to release said holding means under overload conditions.

2. In a circuit-breaker device of the character described, a switch member pivotable between open and closed circuit positions, a circuit-closing contact lever pivoted spacedly relative to the switch member and movable arcuately in a plane parallel thereto between circuit-closing and circuit breaking positions, a tripping member pivoted to said lever and movable in a plane parallel to the switch member movement, spring means urging the switch member to the open-circuit position, a toggle spring compressed between the lever and one end 01' the tripping member so as to urge the latter out of alignment with the lever, means releasably engageable between said switch membeiand said tripping member so as to hold same and the lever in circuit-closing position when the switch member is so disposed, a third spring urging said tripping member and hence the lever out of circuit-closing position against the force of said toggle spring, and a load-responsive device in said circuit movable to release said holding means under overload conditions, said holding means including a component of the switch member movable transversely to the pivotal plane of the switch member, said component adapted to engage and hold the tripping member when the circuit is closed by manual operation of the switch member, means tending to hold said component in transverse position for such engagement, and said component displaceable transversely by said loadresponsive device from engagement with the tripping member upon overload of the circuit.

3. In a circuit breaking mechanism of the type described, a pair oi members separately and spacedly pivoted so as to swing in parallel planes, one of said members movable to open and close the circuit, the other member serving to displace the first member to closed-circuit position, spring means urging each of said members to their inoperative, open-circuit positions, plunger means on one member movable transversely to the planes of pivotal movement of said members between a holding position engaging with the other member to hold both said members in circuit-closing relationship and a releasing position disengaging said last mentioned other member, and a loadresponsive device in the circuit movable under overloaded conditions to move said plunger means to said releasing position.

CLAUDE ROUSSEAU.

REFERENCES CITED UNITED STATES PATENTS Name Date Rypinski Dec. 7, 1943 Number 

